Many processes require a pressurized feed of a solid material. For example, power generation systems typically require a high pressure coal feed. To assist in pressurizing the solid material, the solid material may be mixed with a carrier fluid, such as water, to form a slurry. The slurry includes particles of the solid material suspended in the carrier fluid. The slurry can then be pumped and pressurized to a required high pressure.
Coal and water are one type of common pressurized slurry. However, the pressurized slurries of coal and water are typically highly viscous, thus increasing the pressurization and transport of such slurries. In addition, by using water as the carrier fluid of the slurry, there may be energy penalties (i.e., losses of energy due to the heating of the water) in processes that require thermally processing the slurry.
Various systems have been developed to provide a high pressurized feed of solid material; however, there are currently no reliable systems for providing a continuous supply of the high pressure feed of solid material. One system commonly used to pressurize a solid feed stream is a lock hopper feeder system. With this type of system, the hoppers containing the solid are first pressurized and then emptied into a pressurized system. After a first hopper is emptied, the system is closed, then a second hopper is pressurized and then emptied into the pressurized system. Because each hopper must be pressurized before being introduced into the pressurized system, this system provides only a substantially discontinuous feed of the pressurized solid.
Accordingly, there exists a need for a method and system that will enable an efficient, continuous pumping of a solid material.